What is Skin Inflammation? What Causes it?

By Kylie Nicholson

JAN 23, 2023

Inflammation is a key tool in our immune system’s toolkit, helping our bodies to heal, prevent infection, and fight foreign invaders. Our skin, being the first defense against our external world, works closely with the immune system to alert it to potential threats and take action against foreign invaders such as microbes or even cancerous cells.

Inflammation is the immune system’s response to external threats and kicks off the healing process. In skin, inflammation can have many feelings and appearances, such as skin rash, redness, or warmth in response to external and internal conditions, such as infection, allergens, or abrasions.¹

Inflammation is a sign that that body’s immune system has been activated and is working to fight off foreign entities. The skin harbors an elaborate network of defenses designed to protect the body against outside invaders. As well as acting as a physical barrier against the outside world, skin contains immune cells that are crucial for preventing skin infection and restoring damaged skin tissue. These immune cells promote tissue function and can initiate immune responses in case of injury to the skin or infection.²

When an immune response is initiated, the body produces inflammatory cells and cytokines (substances that stimulate the inflammatory response) to remedy the issue that initiated the immune response. These cells then work toward restoring the health of the skin by trapping bacteria and pathogens, or by rebuilding the tissue structure. This can result in visible signs of inflammation, such as bruising, swelling, and redness.³ Some types of inflammation, especially acute inflammation, can be beneficial. Acute inflammation occurs when there is an immune response initiated by an injury to the skin or the presence of pathogens. The inflammatory response then works toward healing the injury or eliminating the pathogens to restore the body back to health.³However, inflammation can also be problematic when the response is being initiated without an injury or pathogen present, and remains for a sustained period of time. This is known as chronic inflammation, when the body continues to produce these inflammatory cells without cause. These cells can attack healthy tissue and cause sustained damage to the body.³ Some common causes of inflammation in the skin include extreme temperatures, allergens, and stress. Rashes are a sign of inflammation and can be triggered by exposure to poison ivy, poison oak, or other irritants. Medicinal drugs can also trigger inflammation, typically in the form of rashes.⁴

Allergens that cause inflammation often cause reactions in the skin such as eczema (atopic dermatitis) or hives. These skin conditions can be caused by plants, latex, or personal care products such as soaps, laundry detergents, or makeup.⁵

Photosensitivity is another immune response to sun exposure, which can cause inflammation in the skin. This occurs when the body responds to the sun as if it is a foreign invader, and can be induced by some medicines, skin products, or immune conditions. This is separate from sun damage, or sunburn.⁵

Inflammation in the skin often appears as a rash, which can change in appearance depending on the cause of the inflammatory response. These rashes can appear smooth or scaly in texture, and have bumps and/or have a red appearance. Blisters or pimples may also appear in the affected area, and skin can appear raw or cracked. Skin may also thicken in the affected area.¹ Inflammation can also cause skin to be dehydrated, leading to cracks due to dry skin and may bleed.⁶ When an area of skin is inflamed, it might feel itchy, dry, or have a stinging or burning sensation. The area may also feel warm to the touch. ¹ Hives are raised, red bumps that feel itchy, and can swell, especially when located on the face. Psoriasis is a type of skin inflammation that is characterized by raised red skin with white scaly patches. Eczema is another common skin condition that has a dry, itchy feeling with a red appearance.⁷ The top 3 symptoms of inflammation in skin include:

• Redness: Extra redness in inflamed skin is caused by an influx of red blood cells to the area. These extra blood cells will fight infection and encourage healing.⁸
• Rash: A skin rash can often be caused by skin inflammation. These rashes can be smooth, scaly, or bumpy, and can be flat or raised off the skin.¹
• Pain: Inflammatory chemicals can stimulate nerve endings, which can lead to an inflamed area feeling painful. These areas can feel sensitive to touch.⁹

At the intersection of gut health and skin health, there are several highly inflammatory foods that can further contribute to deterioration of the gut lining, which can ultimately impact our immune system’s response that eventually shows in our skin.

• Fried foods: Fried foods often contain high levels of compounds such as advanced glycation end products, which over time can cause acute inflammation and lead to chronic disease.¹⁰
• Sugar and high fructose corn syrup:High fructose corn syrup has been shown to increase several inflammatory markers in both mice and human studies. Sugar can also be harmful because it contains excess amounts of fructose.¹⁰
• Alcohol: Consumption of more than two alcoholic beverages in a day may lead to large increases in inflammation markers. Therefore, limiting alcoholic beverage consumption can help lower symptoms associated with acute skin inflammation¹⁰
• Refined carbohydrates such as white bread, pastries, and foods with high sugar contents.³ These carbs have had their healthy fibers stripped away during processing, and therefore have a higher glycemic index than unprocessed carbs. These refined carbohydrates raise blood sugar quickly and can increase inflammation markers.¹⁰

So, how can you reduce skin inflammation and redness? There are several foods that have anti-inflammatory properties and can lower inflammation responses when included regularly in a diet. These foods include oily fish, leafy green vegetables, olive oil, and tomatoes. Also, limiting alcohol consumption, exercising, and reducing or quitting smoking are ways to lower inflammation throughout the entire body.³ Specific to an inflammatory skin condition, medicines such as antihistamines can be beneficial for reducing chronic inflammation and managing symptoms from conditions such as an allergic reaction. Lastly, managing stress and utilizing relaxing practices can help lower skin inflammation such as the use of cold compresses, phototherapy, and dry skin treatments. ¹ Using the right topical skin care products regularly can also help decrease inflammation caused by skin dryness.

• Inflammation can manifest on skin in many ways, including in rashes, skin redness, dryness, and soreness of skin.
• Many different conditions such as allergies, stress, sun exposure, and poor diet can lead to inflammation throughout the body and skin.
• Inflammation can feel itchy, dry, and painful.
• Several lifestyle changes such as reducing fructose and alcohol intake, and managing stress can lower inflammation and its symptoms.

By Kylie Nicholson: Kylie is studying Biosystems engineering at the University of California, San Diego. She is passionate about scientific writing and women's health research.

References:

1. https://www.healthline.com/health/skin-inflammation
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6515324/
3. https://my.clevelandclinic.org/health/symptoms/21660-inflammation
4. https://www.hopkinsmedicine.org/health/wellness-and-prevention/rashes-and-skin-inflammation
5. https://www.verywellhealth.com/skin-inflammation-5095859
6. https://affderm.com/what-causes-skin-inflammation/
7. https://www.healthhub.sg/a-z/diseases-and-conditions/636/inflammatory-skin-conditions
8. https://www.healthline.com/health/skin-redness
9. https://www.verywellhealth.com/signs-of-inflammation-4580526
10. https://www.healthline.com/nutrition/6-foods-that-cause-inflammation#1.-Sugar-and-high-fructose-corn-syrup